Point constraint will make the child mimic the translates of the parent

Orient constraint will make the child mimic the Rotation of the parent

Parent constraint will make the child mimic the both Rotate and translates of the parent.

Scale is scale

And aim is the only real tricky one, It orients the child so that one of it's axis (determined when creating the constraint) is always pointing directly at the parent (a good example is an eye controller, so the eyes always look at there the controller is positioned)

trick with constraints is that the selection is backwards, Parent first, then child, while normal parenting is child, then parent.